1. Field of the Invention
The present invention relates to a communication game system. More particularly this invention relates to a preferred communication game system for a competitive game in which objects such as vehicles in a three-dimensional virtual space are driven in response to players' operations and the players compete for the best driving time.
2. Description of the Related Art
Along with the recent development of computer graphic technology, simulation devices and game devices for both business and domestic uses have become widespread in the public realm. As one genre of these devices, there is a driving (car racing) game for competing for the fastest lap time by moving a vehicle as an object along a course set in the three-dimensional virtual space (game space), and this game is highly popular.
A simulation device or a game device for playing this type of game (hereinafter referred to as the “game device”) usually comprises: a main game device which contains a computer device for executing a prestored game program; a controller for giving operation signals to the computer device for instructing the movement of the object to be expressed in the game; a display for displaying picture images along with the progress of the game as the game program is executed by the computer device; and a sound device for generating sounds along with the progress of the game.
With this game device, an object such as an automobile is displayed on the display assuming the player as a driver. The player operates the controller and provides the computer device with information such as the driving path and the driving speed. The computer device calculates in real-time the behaviors of the automobile in accordance with this operational information and obtains image data in a driving state and displays the image data on the display.
Regarding the driving game, a competitive communicative type has been in the spotlight in recent years. In the communicative game system for conducting such communicative competition, game devices (clients) operated by individual players are connected to a common game server system via communication lines, thereby forming a server-client system. The system is structured such that the game server system and each client cooperate in executing the game processing based on a specified communication protocol, thereby enabling a competitive game to be played among players in distant places.
However, when the conventional communicative game system executes a driving game, the game server system and the game devices (clients) must send and receive the driving data (position of vehicles, speed, etc.) almost in real-time and each game device must generate image data based on the driving data sent from the game server, by conducting processing which includes determination of hitting (collisions with) other vehicles and calculations of behaviors upon such hitting, and also display the image data in sequence. Accordingly, the calculation load of the game device is increased considerably. Therefore, the more detailed collision determination and detailed behavior calculations are intended, the more delays in image processing and the more omissions in picture images occur, thereby deteriorating the real-time performance. This causes the players of the game to feel stressed.
On the other hand, in this situation, there is a need for having competitions in which more importance is attached to the player's driving technique than to tactics and interference with other vehicles during a race. However, the conventional game system of competitive communicative type does not satisfy such need.
Regarding an image processing device for performing a game of this type, a simple model for collision determination, for example, a sphere, is sometimes set for each object upon determining whether objects overlap one another (such determination is sometimes called hitting or collision determination) If the determination of collisions among the forms of objects is to be conducted without using such collision models, required data and data processing load are increased, and therefore, “the data amount to be sent and received is so considerable that the communication load is adversely affected.” Moreover, delays in sending and receiving data occur and the data amount to be sent and received is increased considerably, thereby delaying the image processing operation. Particularly in a high speed car racing game, even a moment of delay in the image processing operation results in causing stress to the player. Moreover, even when the simple collision model described above is used, calculations of collisions become a considerable load for the image processing device.
The present invention is devised in light of the situation that the conventional technology has faced. It is an object of the present invention to provide a game system of communicative competitive type which can cut down the processing amount of the system, secure the full real-time performance of game processing and display, and deal with the new tendency to focus on operational techniques of players.